1. Field of the Invention
This invention relates to the blow molding of a hollow plastic article, and in particular to a method and apparatus for the blow molding of elongated, serpentine, hollow articles.
2. Discussion of the Prior Art
In general, it is difficult to mold long, serpentine, hollow articles. The normal procedure is to use a large diameter parison, and the loading of such a parison into the mold presents problems since the parison can stick to the sides of the mold cavity. Moreover, a large diameter parison must be used, i.e. the parison must have a diameter equal to the total width dimension of the article, and consequently a large volume of flash is produced. The flash must be trimmed and recycled. U.S. Pat. No. 4,239,474, which issued to T. Nakagawa on Dec. 16, 1980 describes a method in which a mold is loaded by dispensing a parison from an extruder into the open, moving mold. Thereafter, the mold is closed around the parison, and air under pressure is applied to the interior of the parison to blow mold an elbow pipe. The apparatus involved is, of necessity somewhat complicated and cumbersome.
The object of the present invention is to offer a solution to the above identified problems by providing a relatively simple apparatus, which can be used to blow mold hollow articles having complicated, i.e. other than straight shapes.